Tandem Stop Codons in Ciliates That Reassign Stop Codons

Tandem stop codons are extra stop codons hypothesized to be present downstream of genes to act as a backup in case of read-through of the real stop codon. Although seemingly absent from Escherichia coli , recent studies have confirmed the presence of such codons in yeast. In this paper we will analy...

Full description

Saved in:
Bibliographic Details
Published in:Journal of molecular evolution 2009-04, Vol.68 (4), p.424-431
Main Authors: Adachi, Marie, Cavalcanti, Andre R. O.
Format: Article
Language:English
Subjects:
Animal Genetics and Genomics
Animals
Bacteria
Biomedical and Life Sciences
Cell Biology
Codon, Terminator - genetics
Databases, Genetic
E coli
Escherichia coli
Evolutionary Biology
Gene Expression
Genes
Life Sciences
Microbiology
Molecular biology
Paramecium
Paramecium tetraurelia - genetics
Plant Genetics and Genomics
Plant Sciences
Poisson Distribution
Protein Biosynthesis
Sequence Alignment
Sequence Analysis, DNA
Studies
Tandem Repeat Sequences - genetics
Tandem Repeat Sequences - physiology
Tetrahymena
Tetrahymena thermophila - genetics
Yeasts
Yeasts - genetics
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Tandem stop codons are extra stop codons hypothesized to be present downstream of genes to act as a backup in case of read-through of the real stop codon. Although seemingly absent from Escherichia coli , recent studies have confirmed the presence of such codons in yeast. In this paper we will analyze the genomes of two ciliate species— Paramecium tetraurelia and Tetrahymena thermophila —that reassign the stop codons TAA and TAG to glutamine, for the presence of tandem stop codons. We show that there are more tandem stop codons downstream of both Paramecium and Tetrahymena genes than expected by chance given the base composition of the downstream regions. This excess of tandem stop codons is larger in Tetrahymena and Paramecium than in yeast. We propose that this might be caused by a higher frequency of stop codon read-through in these species than in yeast, possibly because of a leaky termination machinery resulting from stop codon reassignment.
ISSN:0022-2844
1432-1432
DOI:10.1007/s00239-009-9220-y